A well-known methodology, that has also been extended to the infinite-dimensional
scenario, is the combination of the port-Hamiltonian (pH) system representation
with energy-based control. In this regard, in particular a pH-system
representation based on an underlying jet-bundle structure, see e.g.
[1]}, [2]}, [3]}, as well as a
formulation exploiting Stokes-Dirac structures, see e.g. [4]}, [5]},
have turned out to be especially suitable. For a detailed comparison
of these approaches, where the main difference is the choice of the
variables, the interested reader is referred to [6]}
or [7]}. In fact, with respect to boundary-control systems,
a lot of literature is available, see e.g. [8]}, [9]}
and [10]}, [11]}, where boundary controllers
based on the well-known energy-Casimir method are designed within
the jet-bundle and the Stokes-Dirac approach, respectively. Moreover,
recently the pH-system description has also been exploited with regard
to the observer design, see e.g. [12]}, where a pH-based
observer-design procedure for boundary-control systems has been developed
within the Stokes-Dirac scenario. In light of the observer design,
of course stability investigations play an important role, since it
must be ensured that the observer error tends to zero.
